says, “Are we there yet?” At the point of no return?Because of your enviable brain power, you’re probablythinking that a pilot might get in trouble if he just keptflying outbound on that 277 degree radial and began hisprocedure turn a hundred miles from the VOR. You’reright (proving once again that Ginko biloba actuallyworks). That’s why procedure turns always come withdistance and speed (200 knots IAS) limitations in refer-ence to a specific point on the approach structure.Anything beyond is no man’s land; go there and “no man”is guaranteed to land.

Flying a procedure turn at the speed of sound wouldsurely result in a sound—the sound of an airplane bor-ing into the side of a mountain somewhere. It might beboring for the airplane, but certainly not for the pilot, towhom it would be totally terrifying. So let’s establishthat far-out point by creating an intersection on theapproach course. There are several ways we can do this,but the simplest is to find a nearby VOR and use a crossradial. It happens that Paradise is nearby (I mean theParadise VOR), so let’s use its 355 degree radial and avery thin black line to establish an intersection thatwe’ll call NORCO, as shown in Figure 14.

Procedure Turn LimitationsA TERPs specialist will look at the nearby terrain and

establish a limit from a specific fix or point within which

the procedure turn must remain (NORCO in our exam-ple). This limit is normally 10 nautical miles. For now,let’s agree that this will work for our VOR approach toRunway 9 at Riverside. Of course, this distance limitmeans nothing if you aren’t aware of it. Fortunately,the “let’s hide the procedure turn distance from thepilot” gag is no longer a favorite pastime of TERPsspecialists. That’s why this information is usuallyfound in the chart’s profile view (Figure 15).

Since NORCO is the place where the procedure turnofficially begins, we’ll also label it as the initialapproach fix or IAF (IAFs are always labeled onapproach charts with the letters IAF in parentheses).In case you’re wondering why you need to identify aninitial approach fix, think back to the FAR section thatdiscussed lost communications procedures. Recall thatyou are required, under certain circumstances, to pro-ceed to the fix from which an approach begins (page 8-34). The IAF is this place, and there are often severalIAFs shown on approach charts.

Before we can decide on the minimum altitudes forthe procedure turn, we need to assess the terrain forheight and obstructions. You don’t want your procedureturn to place you at the same altitude used by dirt bikes,do you? We want to be practical about this. We don’twant nor do we need to have the procedure turn done at

Rod Machado’s Instrument Pilot’s Handbook11-10

A fix from which tomeasure the allowable limits oftravel for the procedure turn.

Procedure TurnDistance Limits

Profile View

Fig. 14

Fig. 15

an altitude that keeps us above all obstructionssouth to the Mexican town of Hasta la Vista Bebe.We only need an altitude that keeps us safe at areasonable distance, while turning, based on themaximum procedure turn speed of 200 knots IAS.

So what geometric area would be reasonablewithin which to provide terrain and obstructionclearance? TERPs specialist use a modified geo-metric race-track like pattern consisting of pri-mary and secondary areas of protection to makethis assessment. While we won’t cover this ingreat detail here (read Chapter 14 of RodMachado’s Instrument Pilot’s Survival Manualfor more detail on these and other chartingissues), you can get an idea of how this plays outin Figure 16. The procedure turn area must pro-vide the pilot a minimum of 1,000 feet of terrainand obstruction clearance within the primaryarea and 500 feet within the secondary area(the secondary area tapers to zero protection atthe border).

Perhaps the most important take-away ideafrom this figure is to always make sure you doyour procedure turn on the proper side of theapproach course (the maneuvering side wherethe barb is). Even if you’re a TV evangelistwith a terrain-specialized guardian angel, youdon’t want to do your procedure turn on thewrong side of the approach course. First, yourreinforced hair won’t protect you in a collisionof this magnitude. Second, for all you know,nobody has even considered that side. Couldbe dragons there. Consider it marked“Abandon ye all hope who enter here.” Dantego there.

Chapter 11 - Understanding Approach Charts 11-11

Holding Patterns in Lieu of a Procedure TurnOK, the 45-180 barb-type procedure turn is a very popular means of

course reversal, but it’s not the only way to get the job done. And that’sgood, because it’s not always possible for a TERPs specialist to use it at agiven airport. One reason is that this procedure requires a great deal ofspace. The oval area used by these course reversals can make themimpractical. Any higher terrain that intrudes can require an unreasonablyhigh procedure turn altitude. This, in turn, increases the required rate ofdescent on final, which has definite limits under the TERPs standards.

Enter the holding pattern used in lieu of a procedure turn.The holding pattern shown to the right is an excellent means of course

reversal because it uses much less space to get pilots reversed and oncourse. Given that instrument pilots know how to enter a holding pattern,they can easily cross the fix from which the holding pattern begins, enterthe pattern via one of the three methods described in Chapter 6, reversecourse and be set up to fly the approach course inbound.

The one major difference about the holding pattern versus the 45-180barb-type procedure turn is that the holding pattern must be flown exact-ly as shown on the chart. Freelance efforts to create your own holding pat-tern will not be applauded by ATC. If you need to express yourself creatively, take up ceramics—after you land. While you can tech-nically do any type of course reversal when the 45-180 is used (i.e., you could do a 90-270 degree turn if it brings you great pleas-ure), you must fly the holding pattern as given, such as using one minute legs as shown above.

On the other hand, everything else we’ll discuss about procedure turns still applies to the holding pattern.As a side note, in Chapter 12, you’ll learn that the 45-180 barb-type procedure turns aren’t used in GPS approaches.

The primary area in whichthe procedure turn is con-

ducted provides 1,000feet of terrain and

obstruction clearance. Thesecondary area provides

500 feet of the same.

Fig. 16

Looking at Figure 17(and using other topologicalc h a r t s t h a t I h a v e n ’ tshown), a TERPs specialistwould probably find thatthere are no obstac lesstanding at an altitudegreater than 2,000 feeta l o n g t h e w e s t w a r d -extending approach course(which is officially referredto as the approach proce-dure track) for the antici-pated distance of the pro-cedure turn. Therefore,the charting specialistwould add 1,000 feet ontothe terrain and obstruc-tion clearance height of2,000 feet and make thisvalue 3,000 feet, the mini-mum altitude for the pro-cedure turn.

Figure 18 shows the chart’s profile view indi-cating a minimum of 3,000 feet for the proce-dure turn. The line under 3,000 feet means thatthis is a minimum altitude. You can remainhigher if you like, but you can’t go any lower (noteven if you have a TV evangelist hair helmet).

Once you’ve completed the course reversaland are established inbound to the VOR on theapproach course, you can descend to a mini-mum altitude of 2,100 feet (where the TERPsspecialist has determined there are lowerobstacles along this route) if you wish, asshown in the profile view. Take a second tolook at the symbology in the profile view. Thethick, downward, right-to-left sloping lineleading outbound from NORCO (Figure 18,position A) signifies the procedure turn and itsminimum altitude of 3,000 feet. The approachcourse line (downward, left-to-right sloping)leading inbound to NORCO (Figure 18, posi-tion B) signifies completion of the procedureturn (when you’re established on the 277degree radial inbound to RAL VOR), thusallowing a lower altitude of 2,100 feet prior toreaching NORCO intersection.

Now, I hope you like to get down, too. Thisdoesn’t mean dancing. It’s almost alwayswise to descend to the lowest altitude permis-sible on any given portion of an instrumentapproach. First, because you don’t want tohave to make a last-minute plunge for theasphalt (or concrete). Second, because thecloser you get to the runway vertically, thebetter chance you have of seeing the asphaltor concrete and being in a position whereyou can safely descend and land on it. That

Rod Machado’s Instrument Pilot’s Handbook11-12

The profile view belowshows the minimum alti-

tude for the procedure turn(3,000 feet MSL) and the

minimum altitude at whichto track the approach course

inbound (2,100 feet MSL).

Fig. 17

Fig. 18

The Approach Procedure Track to Rwy 9 at Riverside

A

B

is the objective, isn’t it? You don’t want to fly aninstrument approach and not land because you didn’tget low enough. Imagine saying to your passen-gers, “The four planes ahead of us landed, but theywere 2000 feet lower, which might be why theycould see the airport. I just didn’t want to getdown today.”

Feeder RoutesThere’s one little problem we need to address

before continuing to draw our chart. What is theminimum altitude a pilot should fly from RiversideVOR to NORCO intersection? This isn’t covered inour profile view, right?

Figure 19 provides the answer. A TERPs special-ist will evaluate the local terrain and decide on asafe altitude for the route from Riverside VOR toNORCO via the Riverside VOR 277 degree radial.Then he’ll create something known as a feederroute, to make the transition clear to the pilot.Think of a feeder route as feeding you onto the ini-tial approach structure via the IAF. Feeder routes

always contain the altitude, direction and dis-tance necessary to make a transition from onepoint to the next on a chart. These routes aretypically identified by a medium thick black lineand have altitude, direction and distance infor-mation listed nearby. In Figure 19, the feederroute from the Riverside VOR is offset slightly(known as a charting offset to make it clearwhat you’re supposed to do here) from themain approach course and indicates a mini-mum altitude of 4,000 feet and a direction of277 degrees for 3.7 nautical miles to NORCOintersection (distances on feeder routes areplaced in parenthesis to prevent confusionwith altitude values, just as I’ve placed thissentence in parentheses to identify it as a sep-arate but important thought).

Now that we’ve created the basic instru-ment approach structure, we should consideran additional and alternative method of get-ting onto the approach course at Riverside.Said another way, we need to build more feed-er routes so we can transition from othernavaids, intersections and airways onto ourapproach course at Riverside. We’ve alreadycreated a procedure turn, which allows us ameans of course reversal in case you arrive atRiverside VOR from a direction other thanthat of the inbound approach course. Forinstance, what would happen if you are on anearby airway or at a nearby navaid andwant to transition onto the approach? Let’sfind out.

The nearest NDB is named PETIS (Figure20). It would be nice if we could have a tran-sition from this NDB to the approach struc-ture. After all, it’s in the best interests of all

Chapter 11 - Understanding Approach Charts 11-13

A feeder route from the RALVOR to NORCO intersectionis shown as a charting off-

set. This route indicates a mini-

mum altitude of 4,000 feet MSL,a distance of 3.7 miles and a

direction of 277 degrees.

Feeder Route

PETTIS NDBis a local navaidfrom which a feederroute might be con-structed allowingpilot self-navigationonto the approachstructure.

Fig. 20

Fig. 19

Navaids That Help Create Feeder Routes

instrument pilots to have as many feeder route transitionson the chart as possible. Remember, the assumption isalways that you will have to do your own navigation, withno choice for getting from enroute to approach other thanvia feeder routes (look ma, no radar!). Does the radar real-ly stop working on occasion? You bet it does. Nothing’sfoolproof. Someone could spill their mocha milk-a grandesupremo coffee on the circuitry, causing circuitry seizure ina puff of mocha milka java smoka (it would take a skilledelectrician who uses Maxwell’s equations to fix it, too).

On one occasion in Southern California, the local TRA-CON was nearly evacuated because of an approachingwildfire. It was out of the fire for the controllers, and intothe frying pan for the pilots. In situations like that, pilotswould be given instructions to fly certain transitions ontothe approach structure, then cleared to fly the instrumentapproach, all without the aid of a radar controller. Yes,boys and girls, once upon a time it was all done that way.

You could, for example, be instructed to proceed to theRiverside VOR at 5,000 feet, and then be cleared for theVOR Runway 9 approach to Riverside. Given this clear-ance, as far as the controller is concerned you’ll fly to theRiverside VOR at 5,000 feet, then track outbound on the277 degree radial and descend to 4,000 feet, descend to3,000 feet once past NORCO, fly the procedure turn, andonce established inbound on the 097 degree course toRiverside, descend to 2,100 feet and complete theapproach. The system works without radar because con-trollers can keep airplanes separated by the use of pilotposition reports, as they did in the early days of aviation(and I don’t mean last Tuesday, either).

By reviewing local terrain information and the avail-ability of nearby navaids, a TERPs specialist can constructseveral feeder routes to help pilots transition onto theapproach course. One example is the feeder route fromPETIS, shown in Figure 21. It looks like a bearing of 200degrees and a minimum altitude of 5,000 feet for 7.5 nau-tical miles will work, given the local obstructions and ter-rain. Since the transition begins at the NDB, it is flown byADF bearing to the Riverside VOR and not a radial orcourse to the VOR. You just have to use a little commonsense to figure this out.

It’s possible and even likely that if you were in the vicin-ity of PETIS NDB, the controller would request that youproceed direct to the NDB, and then clear you for the VORRunway 9 approach to Riverside. If that happened, you’dfly direct to PETIS, track the 200 degree bearing toRiverside VOR and descend to 5,000 feet, turn and trackoutbound on the 277 radial from Riverside VOR anddescend to 4,000 feet until reaching NORCO, thendescend to 3,000 feet, fly the procedure turn and then,once established inbound on the approach course, you’ddescend to 2,100 feet and fly the approach (more on thislast part later). And you’d do it all on your own, withouthaving the controller there to give you radar vectors ontothe approach course.

It’s important to remember that only medium thicklines (i.e., feeder routes) and maximum thick lines (initialapproach segments and approach procedure tracks) have

altitudes and distances associated with them. This meansyou can fly these routes on your own using your own nav-igation. Said another way, a route shown on the approachchart isn’t flyable using your own navigation if that routeis associated with only a very thin line (a thin line, onethat is .007 inch thick, is typically used to identify anintersection or show a VOR radial/course).

For example, given the completeness of our chart at thistime, the 355 degree radial from Paradise VOR (thin line,Figure 21) isn’t flyable because it doesn’t have medium ormaximum thickness. More important, it doesn’t have analtitude, direction, and distance associated with it. That’sbecause the Paradise VOR 355 degree radial forms NORCOintersection. Just think of the medium (.01 inch thick) andmaximum (.02 inch) thick lines as advertising signs. Theyprovide you with information. They say you can fly theseroutes using your own navigation. It’s kind of like a signoutside Bubba Bob’s restaurant that says, “Eat at Bubba’s.5,000 flies can’t be wrong.” That tells you something. Itsays don’t eat there unless you’ve had a tetanus shot.

Feed Me More Feeder RoutesSince we’re constructing feeder routes, we should, how-

ever, try to establish one from the Paradise VOR onto theapproach structure via NORCO intersection. After all, theParadise VOR is a major VOR in the Los Angeles basin(pilots love saying they’ve flown over Paradise) and it hasseveral major airways passing through it, as shown inFigure 22. By examining local terrain and obstructions, aTERPs specialist will create a feeder route using the 355radial from Paradise and having a minimum altitude of3,200 for a distance of 3.5 nautical miles, as shown inFigure 23. Because this is now a flyable route, it gets itsown medium thick line with an arrow. About all it lacks isa merit badge. Or, if it misbehaves, a demerit badge.

Of course, bright student that you are, you may be won-dering why we didn’t create a route from the ParadiseVOR to the Riverside VOR, instead of creating a routethat goes to NORCO intersection. After all, there’salready a feeder route that starts at the Riverside VOR.Wouldn’t it just be better to go from PDZ VOR toRiverside VOR and fly the depicted feeder route out-bound? Not necessarily. First, it’s always better to havefeeder routes onto the approach structure begin at majorintersections or navaids on the chart. This provides a pilotwith more choices, makes his and everyone else’s job eas-ier, makes the world a happier place, causes flowers tobloom better, and birds to sing louder. In other words,isn’t it better to have 10 freeway onramps in a big cityinstead of just one?

The second reason is that TERPs specialists designtransitions to the approach structure so that pilots don’tturn more than 120 degrees to become established on theconnecting segment (in fact, 120 degrees is the maximumallowable limit for turns made when transitioning fromone electronically navigated route to another). Headingfrom PDZ to Riverside VOR, then tracking outbound onthe approach course requires a turn of approximately 130degrees. It’s just a lot cleaner and simpler to establish thePDZ transition directly to NORCO intersection.

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Chapter 11 - Understanding Approach Charts 11-15

A feeder route fromPETIS NDB allows a

pilot to fly to RAL VORat a minimum altitude of 5,000 feetMSL on the 200 degree bearing for

a distance of 7.5 nm.

A feeder route from PDZVOR allows a pilot to fly

to NORCO intersectionat a minimum altitude of 3,200 feetMSL on the 355 degree radial for a

distance of 3.5 nm.

Feeder Route

Feeder Route

Paradise VOR

The Paradise VOR has many airways that runthrough it. As a result, this VOR can provide several feed-er route transitions for the many airports having instru-

ment approaches in the Southern California area. Fig. 22

Fig. 23Fig. 21

According to Figure 23, we nowhave three feeder routes shown onthe chart’s plan view. One begins atParadise VOR, the other at RiversideVOR and the last at PETIS NDB.Each leads you to a point where youcan intercept the approach courseoutbound (the Riverside 277 degreeradial) and fly the procedure turnbefore proceeding inbound.

In Catholic school, a nun onceasked me to use “ominous” in a sen-tence. I stood up and said, “Ominousguy.” Later, in the emergency room,as I regained consciousness, I under-stood what ominous really meant.While it might not be ominous if anapproach chart didn’t have addition-al feeder routes to help you transi-tion from the enroute to theapproach structure, it would cer-tainly be a shame. So let’s do whatTERPs specialists do and build addi-tional feeder routes onto theapproach structure, where possible.Before we can do this, we need tosolve the problem of charting scale.

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The Five Segments of an Instrument ApproachInstrument approaches consist of five parts or segments, each with its own symbols, rules, customs and quirks. The five segments

are the feeder route, initial approach segment, intermediate approach segment, final approach segment and missed approach seg-ment, as shown in the figure on the right.

Each segment is designed to allow youto safely and comfortably accomplish thespecific objective of approaching an air-port in IFR conditions. In much the sameway that a staircase allows descent onestep at a time, instrument approacheslower you in an orderly and progressivefashion. In aviation, it’s a five-step pro-gram. If you understand the specific pur-pose of each instrument approach proce-dure segment, you will better understandhow to execute the procedure.

The basic idea of all the segments mak-ing up an instrument approach is to takeyou from wide, expansive airways that aremiles in width to fine, precision-like navi-gational tunnels. Vertical and horizontal tolerances, speeds, and margins of safety all become smaller and more critical as youapproach the runway. The various segments are designed with this in mind. They take you from the lofty-above and return you backto the surly bonds of earth. And they do it step by step, with forgiveness for excursions growing ever more stingy. As you get closeto the runway, you lack slack.

Approach segments are flown in a specific sequence, as shown in the figure above. Size may not matter, but order definitely does.Starting with the feeder route, the aircraft is taken to an initial approach fix (IAF). IAFs are usually identified on the plan view of theapproach chart. Initial approach segments start at the initial approach fix (IAF), and proceed to the intermediate fix (IF). IAFs arelabeled with the letters (IAF), intermediate fixes are labeled with the letters (IF) on U.S. approach charts. The intermediate segmenttakes you to the final approach fix (FAF). While the initial approach segment may give you 1,000 feet of terrain and obstruction clear-ance, obstacle clearance may be as low as 500 feet on the intermediate segment. I told you tolerances would get tight.

When the final approach fix (FAF) exists, it is identified by a Maltese cross in the profile view of the chart. This is the place where yourfinal descent to the lowest minimum altitude permissible on the approach begins. When the missed approach point (MAP) is reached,if you can’t meet the legal landing criteria then the missed approach segment takes you to the missed approach holding point.

How Terrain and Obstructions are Depicted on the Plan View The relief features associated with terrain on the approach chart’s plan view are

depicted when that terrain exceeds 4,000 feet above the airport elevation. Terrain mayalso be depicted if,within six nauticalmiles of the airportreference point(ARP), the terrainrises to 2,000 feetor more above theairport. Terrainmeeting thesecriteria is shownbecause it shouldbe of interest to thepilot (especially ifthat pilot’s airplanedoesn’t have aforce field).

Normally, terrainwill be depicted byfive or less tints ofbrown, with con-secutively darkertints representinghigher terrain ele-vation contours.Contour levels of1,000 feet are usedin this presentation.

Terrain more than 2,000 feet higherthan the airport elevation lyingwithin six miles of the airport.

Terrain more than4,000 feet above the

airport elevation.